Patents Assigned to University of Waterloo
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Patent number: 5852172Abstract: A plurality of polypeptides derived from intercellular spaces of plant cells having frost tolerance. Some of the polypeptides are ice nucleators for developing ice crystals in extracellular spaces of plant tissue, some of the polypeptides are antifreeze components which control ice crystal growth in extracellular spaces and some of the polypeptides are enzymes which adapt plant cell walls to function differently during formation of ice crystals in plant intercellular spaces.Type: GrantFiled: April 10, 1995Date of Patent: December 22, 1998Assignee: University of WaterlooInventor: Marilyn Griffith
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Patent number: 5825230Abstract: A switched-capacitor gain-boost network includes a bank of N-substantially identical sampling capacitors connectable to an output node. An integrating capacitor has one node connected to a low potential node and a second node connected to the output node. The integrating capacitor is connected to the bank of sampling capacitors in parallel when the bank of sampling capacitors is connected to the output node. Sampling period switches are actuable during a sampling period to connect the sampling capacitors of the bank in parallel and to connect the bank between an analog signal input node and a low potential node to charge the sampling capacitors. Integrating period switches are actuable during an integrating period to connect the sampling capacitors of the bank in series and to connect the bank between a low potential node and the output node to dump the charge stored by the sampling capacitors onto the integrating capacitor. A method of providing dc gain to an analog input signal is also provided.Type: GrantFiled: August 22, 1997Date of Patent: October 20, 1998Assignee: University of WaterlooInventors: Feng Chen, Bosco Leung
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Patent number: 5782583Abstract: The barrier is waterproof, and is used to contain contaminated groundwater within an enclosure. Steel elements are pile driven, the elements having rolled-over forms (5,6) which inter-engage. Upon inter-engagement, an enclosed cavity (90) is created which extends from top to bottom of the piled elements. A scraper (19) on the junior element (8) cleans dirt out of the cavity as the junior is driven down alongside the adjacent senior element (7). The cavity may be cleaned out by inserting a hose pipe to the bottom of the cavity (90) and flushing through with water. Then, a sealant is injected into the cavity, using an injection tube. The inter-engagement of the edge forms (5,6) of the elements is such that the cavity formed by the inter-engagement is constrained to its nominal size and shape throughout the whole height of the barrier.Type: GrantFiled: December 21, 1994Date of Patent: July 21, 1998Assignee: University of WaterlooInventor: E. S. Vales
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Patent number: 5770718Abstract: A cDNA for apt from a plant, particularly A. thaliana has been isolated, purified and characterized. The cDNA is useful for the generation of APRT-deficient mutants and as a probe for APRT cDNAs in other plants.Type: GrantFiled: May 22, 1995Date of Patent: June 23, 1998Assignee: University of WaterlooInventor: Barbara Moffatt
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Patent number: 5732008Abstract: A low power high performance adder using a conditional sum adder (CSA) architecture and complementary pass logic (CPL) implementation. The adder comprises a plurality of blocks, each block including a conditional sum cell and an output multiplexer. Each block except the first, also comprises a block of 2:1 multiplexers intermediate the conditional sum cell and the output multiplexer. The adder according to the present invention operates with lower power consumption and at greater speed than prior art adder architectures.Type: GrantFiled: December 4, 1995Date of Patent: March 24, 1998Assignee: The University of WaterlooInventors: Issam S. Abu-Khater, A. Bellaouar, Mohamed I. Elmasry
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Patent number: 5705787Abstract: An in-torch vaporization sample introduction system for introducing a sample to be analyzed into a spectrometer, comprising a sample holder means for carrying the sample to be analyzed, a modified Fassel-type torch having a plasma fed by inert gas through outer and intermediate feed channels in an enlarged gas tube, an inner axial tube having one end open adjacent the plasma and an opposite end open for receiving the sample holder for feeding the sample to the plasma, the inner axial tube tapering to a reduced diameter adjacent the one end to form a well defined channel for feeding the sample to the plasma. The sample holder is positioned in the inner axial tube a predetermined distance below the plasma, and the opposite end of the inner axial tube is sealed for vaporizing the sample.Type: GrantFiled: August 12, 1994Date of Patent: January 6, 1998Assignee: The University of WaterlooInventor: Vassili Karanassios
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Patent number: 5649373Abstract: A novel shoe structure, particularly a ballet shoe, is provided in which an elongate flat leaf spring element is provided associated with the sole of the shoe structure. The elongate leaf spring extends from the toe region of the shoe structure beyond the location of the metatarsal-phalangeal (m-p) joints of the wearer, so as to provide a mechanical power assist to the wearer at the m-p joints.Type: GrantFiled: June 7, 1995Date of Patent: July 22, 1997Assignee: University of WaterlooInventors: David A. Winter, Paula A. Dozzi
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Patent number: 5641020Abstract: The treatment system involves the use of hydrofracturing in drilled boreholes over the treatment area. The hydrofracturing fluid contains treatment material, of the kind that causes chemical breakdown of the contaminant. The breakdown leads to a contaminant concentration of zero in the hydrofracks, and therefore the contaminant diffuses towards the hydrofracks, where it is in turn broken down. Calculations and measurements indicate whether natural cracks in the ground are far enough apart to make hydrofracturing worthwhile. A formula indicates, from an assessment of diffusion coefficients, etc, whether the contaminant will be rendered safe within a given time period.Type: GrantFiled: May 19, 1995Date of Patent: June 24, 1997Assignee: University of WaterlooInventors: John Anthony Cherry, Beth L. Parker
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Patent number: 5633194Abstract: A low temperature ion-beam assisted deposition process, comprising the steps of cleaning at least one substrate, subjecting the substrate to a vacuum of at least 2.times.10.sup.-4 Torr, heating the substrate to a temperature of at least 280.degree. C., and directing an ion beam at the substrate, wherein the ion beam comprises ion-associated gas molecules of Si or Ge, so as to grow a thin epitaxial film of Si or Ge on the substrate.Type: GrantFiled: April 19, 1995Date of Patent: May 27, 1997Assignee: The University of WaterlooInventors: C. R. Selvakumar, S. Mohajerzadeh, D. E. Brodie
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Patent number: 5624552Abstract: A barrier of sheet metal elements in pile-driven into the ground in the path of contaminated groundwater. The barrier serves to funnel the contaminated water into an aperture in the barrier, in which is located a receptacle. A caisson is driven into the ground at the aperture, and the soil etc. removed from inside. A receptacle is lowered into the empty caisson, and a seal is provided whereby, when the caisson is removed the receptacle is sealed to the barrier. Baskets containing treatment material may be lowered into and hoisted out from the receptacle. Rubber seals seal the basket to the receptacle.Type: GrantFiled: February 22, 1994Date of Patent: April 29, 1997Assignee: University of WaterlooInventors: Enoch S. Vales, John A. Cherry, David J. Lang
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Patent number: 5605551Abstract: A high conversion of biomass, such as wood, sawdust, bark, or agricultural wastes, to liquids is obtained bypyrolysis at short reaction tines in a reactor capable of high heat transfer rates; the reactor being of the fluidized bed, circulating fluidized bed or transport type in which the conveying gas contains low and carefully controlled amounts of oxygen, allowing a reaction system with low concentrations of carbon monoxide or flammable gases with a resulting improvement in operating safety and potential improvement in thermal efficiency and capital costs. The oxidation steps may be carried out in one or two stages. The resulting liquid product may be used as an alternative liquid fuel or as a source of high-value chemicals.Type: GrantFiled: July 31, 1995Date of Patent: February 25, 1997Assignee: University of WaterlooInventors: Donald S. Scott, Jan Piskorz, Desmond Radlein, Piotr Majerski
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Patent number: 5605634Abstract: The system places traces of nutrients and other treatment substances in the ground, in the path of an on-coming plume of contaminated groundwater. Boreholes placed across the plume contain respective diffusion tubes, the tubes being of e.g LDPE, or dialysis tubing. The remediation substance is circulated (pumped) through the diffusion tubes periodically. The remediation substance diffuses through the LDPE into the water in the borehole, and thence into the plume and is carried into the aquifer.Type: GrantFiled: April 24, 1995Date of Patent: February 25, 1997Assignee: University of WaterlooInventors: Ryan D. Wilson, Douglas M. Mackay
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Patent number: 5602774Abstract: A SRAM includes an ECL input buffer connected between an address bus and a W-OR predecoder array. The logic output of the W-OR predecoder array is applied to a level translator array and level shifted. The level shifted output of the level translator array is supplied to a plurality of self-resetting word-line decoder and driver (WLDD) circuits. The WLDD circuits supply activation pulses to selected blocks of memory in a memory cell array. Sense amplifiers sense and latch-in the data stored in the activated selected blocks of memory. The design of the W-OR predecoder array, level translator array, WLDD circuits and sense amplifiers is such to reduce the overall power consumption of the SRAM.Type: GrantFiled: November 16, 1995Date of Patent: February 11, 1997Assignee: University of WaterlooInventors: Muhammad S. Elrabaa, Mohamed I. Elmasry
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Patent number: 5561197Abstract: A process is provided for the hydrogenation of carbon-carbon double bonds in polymers by treatment of the polymer in solution with hydrogen in the presence of osmium-based catalysts.Type: GrantFiled: June 27, 1995Date of Patent: October 1, 1996Assignee: University of WaterlooInventors: Garry L. Rempel, Neil T. McManus, John S. Parent
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Patent number: 5548288Abstract: An improved current cell and current switch is described for use in digital-to-analog converters and other current mode circuits. The current switch is implemented using BiCMOS circuitry which is characterized by an absence of base current error and a switching speed which is approximately twice as fast as the switching speed of prior art MOS-based switches. According to one embodiment, the current cell is implemented in BiCMOS which offers higher output resistance, smaller minimum voltage, and improved accuracy over prior art MOS-based self-calibrated current cells. According to another embodiment, the current cell is implemented in CMOS and is characterized by a significant reduction in charge injection, leakage current and error due to coupling of the cell output voltage back to the storage node, as compared with prior art MOS-based current cells.Type: GrantFiled: December 22, 1993Date of Patent: August 20, 1996Assignee: University of WaterlooInventor: Bosco Lueng
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Patent number: 5534154Abstract: Water contaminated with halogenated organics, including chloroform, trichloroethane, solvents, pesticides, etc. is treated by passing the water through a permeable mixture of activated carbon and iron fillings. When the mixture is brought to a negative Eh voltae, the metal causes the contaminants to undergo chemical breakdown. The activated carbon acts to retard the contaminant, giving it a long residence time close to the iron. The negative Eh conditions demand oxygen exclusion, such that a favoured application is to place the mixture in a trench below the water table in an aquifer, in the path of a plume of contaminant. The mixture may also be contained in a tank above, or in, the ground. An inert filler material, such as sand, may be included in the mixture.Type: GrantFiled: October 22, 1993Date of Patent: July 9, 1996Assignee: University of WaterlooInventor: Robert W. Gillham
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Patent number: 5525916Abstract: An All-N-Logic (ANL) high-speed single-phase dynamic CMOS logic utilizing all-N-logic blocks. According to a first embodiment, a 2:1 frequency divider is provided using the ANL CMOS logic of the present invention. According to a second embodiment, a pipelines 8-bit carry generator is provided utilizing five stacked NMOS gates.Type: GrantFiled: April 10, 1995Date of Patent: June 11, 1996Assignee: The University of WaterlooInventors: Richard Gu, Mohamed Elmasry
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Patent number: 5514279Abstract: A system for treating groundwater contaminated with acidity or other contaminants is disclosed. The system involves excavating a trench into the aquifer in the path of the contaminant plume, and placing a body of active material in the trench. The active material depends on the particular contaminant: organic carbon may be used when the contaminant is ferrous sulphate, or hexavalent uranium oxide, or dissolved nitrate; pyrite or elemental iron may be used when the contaminant is eg chromium oxide. The active material causes the contaminant, by chemical reaction, to change its oxidation-reduction state, and to precipitate harmlessly in the body of material.Type: GrantFiled: October 27, 1994Date of Patent: May 7, 1996Assignee: University of WaterlooInventors: David W. Blowes, Carol J. Ptacek
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Patent number: 5496741Abstract: A device and process for increasing analyte concentration in a sorbent from a source of analytes contained in a sample uses means for increasing a temperature differential between the sample and the sorbent. The sorbent can be a polymeric coating on a substrate. The sorbent is located in a headspace of the sample and has internal cooling means such as liquid carbon dioxide so that the sorbent can be cooled relative to the sample. Preferably, the sample is heated to further increase the temperature differential between the sample and the sorbent. As the temperature differential increases, a partition coefficient of the sorbent/sample also increases. Preferably, the sorbent is located in a headspace of the sample. Previously, for certain analytes, the partition coefficient was too low and the concentration of analytes extracted into the sorbent from the sample was insufficient to provide an accurate measurement of concentration.Type: GrantFiled: April 14, 1994Date of Patent: March 5, 1996Assignee: University of WaterlooInventor: Janusz B. Pawliszyn
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Patent number: 5490743Abstract: For providing an in-ground system for treating contaminated groundwater, of the funnel-and-gate type, a cylindrical caisson is driven into the ground. The native soil is augered out of the caisson, and porous treatment material substituted. The caisson is then withdrawn, leaving a prism of porous treatment material in the ground. A sheet metal barrier element is inserted into the ground, one portion of the element extending into the prism and the other portion into the surrounding soil. More prisms are provided as further treatment gates, and more barrier elements are arranged to funnel the groundwater through the gates.Type: GrantFiled: June 20, 1994Date of Patent: February 13, 1996Assignee: University of WaterlooInventor: Enoch S. Vales